Vibrating equipment



J. H. LINHARDT ETAL Nov. 11, 1952 VIBRATING EQUIPMENT Filed Dec. 17, 1948 2 Sl-IEETSSHEET l INVENTORS f b Lmhar'dl and ATT [\(E'Y Q 1952 .1. H. LINHARDT ET AL 2,617,533

VIBRATING EQUIPMENT Filed Dec. 17, 1948- 2 SHEETS-SHEET 2 f/VVENTORS \Lh Lm/mrdi' and BY Lew/s H. Lehman Patented Nov. 11, 1952 VIBRATING EQUIPMENT John H. Linhardt, Inglewood, Calif., and Lewis H. Lehman, Chicago, 111.; said Linhardt assignor of his interest to said Lehman, as

trustee Application December 17, 1948, Serial N 0. 65,757

3 Claims.

This invention relates to improvements in vibrating equipment. More particularly, this invention relates to an improved method and apparatus that can be used with vibrating equipment to prevent blinding of the separating screens used in such equipment.

It is therefore an object of the present invention to provide an improved method and apparatus that can be used with vibratin equipment to prevent blinding of theseparating screens used in such equipment.

In the operation of vibrating equipment, materials to be separated are customarily placed upon the separating screens or grids of such equipment and vibrated until the small-sized particles pass through the screens or grids and are thus separated from the large-sized particles which cannot pass through those screens or grids. Where the materials which are placed upon the the screens or grids are composed of particles that vary widely in size, the small-sized particles usually pass through the screens or grids rather readily; but where the materials are composed of particles which vary but little in size, the larger particles are not much larger than the openings of the screens or grids and the lower portions of those particles penetrate those openings for substantial distances. This fact frequently causes those larger particles to lodge in the openings of the screens or grids since they can not pass through these openings but have penetrated so far into those openings that they cannot easily rise up and free themselves. The lodgment of large numbers of large-sized particles in the openings of the screens or grids of vibrating equipment. causes blinding of those screens or grids; and blinding materially reduces the through-put of the screens or grids by preventing ready passage of the small-sized particles through the openings of those screens or grids.

Various proposals have been made and a number have been tried; some contemplating frequent stopping of the vibrating equipment to empty or unblind the screen. Other proposals were directed to moving scrapers along the bottoms of the separating screens or grids to force the lodged particles up and out of the openings in those screens or grids. Still other proposals contemplated making the screens or grids as drums that revolved past brushes which forced the particles out of the openings. While some of these various proposals could provide momentary unblinding of the screens or grids, they were not capable ofv assuring truly satisfactory separation of the materials placed upon the screens. The present invention on the other hand, assures effieient blinding-free operation of the screens of vibrating equipment by positioning flexible elements immediately below those screens and by supporting those elements so they can flex and can nudge the lodged particles out of the openings in the screens. This action of the flexible elements will be continuous, and it will prevent lodgment of particles in any of the openings of the screens; thus assuring the small-sized particles full access to all of the openings of the screens. It is therefore an object of the present invention to position flexible elements immediately below the separating screens of vibrating equipment and to support those elements so they can flex and nudge particles tending to lodge in the openings of the screens.

The flexible elements provided by the present invention do not require an outside source of excitation; instead they respond to the vibration imparted to the screens or screen supports to flex and move into and out of contact with the screens. This arrangement provides inexpensive butcertain blinding-free operation of the screens of vibrating equipment.

The flexible elements provided by the present invention are confined and supported immediately adjacent the bottoms of the screens by supports which underlie the flexible elements. These supports hold the flexible elements so closely adjacent the undersides of the screens that they avoid the generation within those elements of unduly large dynamic forces. As a result, the flexible elements are enabled to engage and move those portions, of the particles lodged in the openings in the screens, which project below the undersides of the screens without bruising those particles and without causing them to fly out of the vibrating equipment. It is therefore on object of the present invention to provide flexible elements that are closely confined between the separating screens and the supports that are disposed short distances below those screens.

In many screening and separating operations it is extremely important to avoid adulteration of the material which passes through the screens. Unfortunately, many materials which must not be contaminated have pronounced tendencies toward blinding of the screens. Such materials cannot be screened by many prior methods since adulterants were necessarily introduced during the unblinding operation. For example, where made of that rubber-like material so that if any;

portions of the surfaces of the fiexibleelements were to be abraded or worn, those portions would not adulterate the screened, material;-:the materials being the same.- It is therefore an ob:

ject of the present invention -to-provide flexibleelements adjacent the separating screens of vibrating equipment and to n ake those elements. of material which is the same as, or similar to, the material being screened.

Other and further objects and advantages of =--.th.e present invention should b come.- apparen --fromland examination, of thezdrawing and ac- .companying description.

-;;In .the. drawing. and accompanying. description twopreierred embodiments ofthepresent invention.- are :shownand. described butiit is-tobe understood thatv the. drawing and accompanying a description are. ior -the, purposesgof, illustration ..only-. and :do. not limit .the invention and that :the invention. will :be. defined by. the appendedclaims.

-In. the. drawing, Fig. 1; is, a. partially-broken, perspective view ,of; the deck. of a .vibrating 1dewicemhich.iseequipped with one .type of'zflexi- Ebleelement provided by. the present invention,

.ZEig; 2 .is Jar-broken, cross-sectionaL. 'sideyiew ofgthe; deck of; Fig; 1,

Fig. 3 is a partially-broken,perspective view of anpther deck-v of a vibrating device which is equipped .with'. another type of flexible element -provided bythe present invention and- 4mg. .4 is a cross-sectional, side. view. of the deck ofiFig; 3.

Referring tolthedrawing-indetail, .the longitudinallyextendingangles thatform the sides .of

the deck of a vibrating device are:.denoted.by the Q numeral 0. Transverselyeextending. angles 12 are disposed between the ends-of theangles I0, and the angles -l2 constitute the ends of the deekl -='l2hean'gles-l0 and 12 may be secured to-:

:gether in anumberof different ways, but welding is :preferred since it provides a strong and durable-structure. Also secured to the angles (2 are:longitudinally-extending separators H5; and theseseparatorsarepreferably securedtog. the angles! 2 by welding.

:Disposed between the .separators .l 4 of the deck J areaenumberof perforated-plates H5 which have upturned edgesflllalongthe sides thereof. The

edges l 8 stiffen the plates 16- and permit a large;

recesses 24. The slitting of the supporting elements 22 permits ready insertion and removal of flexible elements 26 into and out of the recesses 24. The recesses 24 are in register with each other to form recesses that can receive and confine the ends of the flexible elements 2'6; the re cess es 124 having smaller radii than the radii --of the flexible elements 25-to enable-the supporting elements 22 to clamp and hold the ends of the flexible elements 26.

The.i1exible elements 26 have their left-hand ends fixedly spaced apart and spaced above the .;plates:;|6:.by.;1the..supporting elements 22. The .-.rest=of -the.=flexible elements 26 can sag down -and rest upon-the; plates IB, and the right-hand ends of the flexible elements 26 are free to move hahopt gn thep lates l6. To prevent twisting and tangling of the right-hand ends of the flexible elements 26, connecting links 28 are secured between those ends. While the flexible elements re ini ially placed parallel: to. each. other as w shown, thoseelemeptsean flex: andlm ve rather --treely..relative..;t0.;;the 19 31385 l6 and.-relative.-j;o .each; other.

. A .porousscreen :25.- is ,securedto theltop edges of angles In and supportingielementsin.andzz23; and thatscreen serves ,to separate;materiallplaced on i aby-.p rmi. ting...the sm ller particlesi-of thematerialto passrthron hi heppeninesiinthe 3o screen-while.lsupportinemthe lar r-:p rticles.'.;on the top of the screen. -tflhescresn.t iiwilblimit upward- 1 mov nt of lithe flexible elements: 2 6, e and [theiplates' z! fi-vwillilimitidownward movement oi thezflexible elements :26 andzthus zthe. elements 26 will. .be closely. confined.adiaeehtzzthesunder z-sur ace .o th .scre neloth 25.

:With thisa rrane men ithe flexiblezwm mber :26 .willbe; able .to. respondtothe ibratiomzimparte ato ztheq eck .by the..v bratineeequ nment 40 .Qfwhie t e d ck-is am mpo nt nartst afiex and movet wardsahd. away ir m the und r surzfaeeh he sem c othllfi. :Beeause.;theflerible aeethos FPDPTILQIAS 10 :th la s e ze pa t cles which pr ,--le th u h peni :in th scr en. cloth 2.5 rthw: ,dir etlyensas th nnd resurfae -.9. fi h .r.eeh -Ql 5- :These;en a ements-M11 impart ppwardly dir cted; impulses. to .th "par- ,55 ticles,on thescreeh and lseep those particles from -,lodging in the openings in screen elothzrziz and b ind n :.tb tp 1t. is desitable: to limit the yforce which "the fle ble 1 elements 61 25.;can :impart .-to gthe, screen 6 19. 9. 3 .12 nd tthespartioles thereon since :those particles might be of such a nature that=:they wouldhehrulsed; orealisedeto-iflyrfrom thescreen. 5ilhe;nre e ri veotioh: provides such limitation b e-p me :th rfl zsible elements. :ze so :close storth s Ben: 1912 1 ha hose lements an- .Q i eve1e exees vemom ntum- Thenmoimt {of dy a ic thre e rate ele entswill rhedetsrmihedr yth d st n e w..-

.- fiah hese e -rc oth n -h the;- exri lity 7.0 ee pth e emen s. whet: h de ree ,offlexibility i es l :r su a ed y prope selection-or :t-he .emet iahs st fin szofthose e ements-and. the d s c sh zpredetermined in each .case. 1 W ere easily bruis ed:=.materials :suchas :peasare 7,5 .;,-.t@he:-.soneened, .:;the. distance-between 11211818028611 cloth 25 and the plates l6 should be less than three (3) inches and the flexible elements 26 should be hollow tubes of fabric, soft rubber, and elastomeric plastic material, or the like. Moreover, the-plates I 6 should be of fabric, rubber, an elastomeric plastic material, or the like so the flexible elements 26 will not crush the peas when the elements 26 flex downwardly toward the plates l6. By being flexible the plates H5 will be able to yield and prevent suchcrushing. Moreover, the openings 20 in the plates l6 are so much larger than the openings in the screen cloth 25 that most of the peas will pass directly through the openings 29. However, no injury will come to thosepeas which are momentarily held by plates I6 since the conjoint yielding of the materials in' plates 16 and in elements 26 will avoid injury to the peas.

Where harder materials, such as coal, crushed or ground nut shells, or the like are to be screened, the plates 16 need not be made of a yielding material but can be made of metal or wood. Moreover, depending upon the nature and character of the material to be screened, the flexible elements 26 can be made solid as well as tubular,

they can be made with various regular and irregular cross sections, and they can be made of bare metal, rubber-coated metal, plastic-coated metal, fabric, or plastic.

The screen cloth 25 shown in the drawing is typical of the woven wire cloths used in many types of vibrating equipment. However, the present invention is not limited to use with screen cloths of this type; instead it is usable with perforated plates, silk screens, soldered wire screens, and the other types of screens customarily used with vibrating equipment.

Among the materials that can be used in the flexible elements 25, the plates i6, and the connecting links 28 are the various synthetic rubbers regenerated celluloses, vinyl acetate and vinyl chloride copolymers, polyvinyl acetates, polyvinyl chlorides, polyethylene, polystyrene, and like materials; and they can be used alone or as coatings on metal elements. It is desirable, wherever possible, to make the flexible elements 26 and plates l6 of material which is the same as, or similar to, the material being screened. In such cases, any abrading of the flexible elements 26 or plates 16 could notadulterate the material passing i through the screen since the abraded material would be of the same or similar character as the screened material. Ordinarily, abrasion of flexible elements 26 and plates I6 is so infinitesimal as to be insignificant; but in those few cases where it is essential to maintain great purity of the screened material, it is desirable to select a material for the flexible elements 26 and plates 16 which will be the same as, or inert in the presence of, the material being screened.

In Fig. l, the flexible elements 26 are shown approximately parallel to each other. those elements may assume that position initially, they will move from side to side and up and down in response to the motion of the deck. In fact, the flexible elements 26 may even overlap each other occasionally; but the connecting links 28 will tend to keep the elements 26 from being entangled.

In Figs. 3 and 4 a modified form of the present invention is shown and described. The number 3!] denotes the longitudinally-extending angles that form the sides of the deck of a vibrating device; and transversely-extending angles 32 are disposed between and secured to the ends of an- While gles 30. Also disposed between and secured to angles 30 are rods 36; and these rods underlie longitudinally-extending separators 34. The angles 30 and 32 are preferably secured together, as by welding; and the separators 34 are preferably welded to angles 32. The rods 36 are preferably seated in openings in the angles 30.

Supports 38 are disposed between the separators 34 at each end of the deck; and those supports are slit along their lengths. The supports 38 are also provided with transversely-extending, semi-cylindrical recesses 46 which are registerable with each other to form cylindrical recesses for the ends of flexible elements 42. The cylindrical recesses formed in supports 38 by recesses 40 will be smaller than the ends of flexible elements 42; thereby facilitating securement of elements 42 to supports 38. A screen cloth 44 is secured gr; the upper surfaces of angles 30 and supports The flexible elements 42, which can be made of the same materials of which the flexible elements 26 of Figs. 1 and 2 are made, are supported at both ends by supports 38. As a result, they can be supported by the spaced rods 36 rather than by perforated plates, such as plates N5 of Figs. 1 and 2. The rods 36 will hold the flexible elements 42 closely adjacent the under surface of the screen cloth 44 and thereby limit the momentum that can be developed in those elements.

It is desirable to make the rods 36 of circular cross section for two reasons. First, such a cross section avoids sharp corners that might tend to cut or abrade the flexible elements; and second, such a cross section will not tend to hold the particles being screened. Instead, the arm-- ate upper faces of the rods 36 will cause those particles to slide off. This avoids bruising of fragile particles being screened.

For purposes of clarity, only three flexible elements were shown in each of the spaces between the separators of the decks. In practice, as many as seven or more of those elements may be used between the spaced separators. Whereas two preferred embodiments of the present invention have been shown and described in the drawing and accompanying description, it should be obvious to those skilled in the art that various changes may be made in the form of the invention without affecting the scope thereof.

What I claim is:

1. In a vibrating screen unit, a frame having side walls and end walls, a screen supported on the top of said Walls, a support secured to the walls and parallel and closely underlying the screen, elongated, flexible, strand-like members of substantial mass secured to an end wall of the frame above the support and below the screen, said elongated members extending along the support over substantially the extent of the screen, with the major portions thereof resting upon the support.

2. In a vibrating screen unit, a frame having side walls and end walls, a screen supported on the to of said walls, a support secured to the walls and parallel and closely underlying the screen, elongated, flexible, strand-like members of substantial mass secured to an end wall of the frame above the support and below the screen, said elongated members extending along the support over substantially the extent of the screen, with the major portions thereof resting upon the support and connecting links between adjacent free ends of said flexible members.

3 3 111 21, vibrating egreen. unit ea Ireme havi ng sidewalls-and end walls, a screen supported on the 00p bf said; walls, a" support secured tq'the .walls a nd parallel and closely underlying the elg geted members extending along the support "over substanbially the extent of the screen, with .the'maijonpprtims thereof resting upon the sup- .pdrt.

' JOHN LINHARDT.

LEWISI-I. LEVI-IMAN.

*BEFEEENCE CITED 5 71 fi l ewine-z-;re. r m ar r o "in h UNITED STATES PA EN S Number I Name ,Date

'7 Sinclair 1 -Ma r.-2 6,i1 867 Binkley V Sept. 3,187 2 Moser et a1. Dec. 13,1881 Dough Dec. 22,1896 Maun Sept. 25, 1900 Butler Sept, 25, 1900 Sherk Aug. 13, 1901 Draver Aug. 11, 1903 Case Jan. 30, 1906 Kibler June 10, 1913 'McDaniel Aug.' 5, 1913 Ingraham Aug. 9, 1932 lli ms July 6, 1937 

